From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 026C2C433FE for ; Mon, 10 Oct 2022 17:27:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229714AbiJJR1T (ORCPT ); Mon, 10 Oct 2022 13:27:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbiJJR1Q (ORCPT ); Mon, 10 Oct 2022 13:27:16 -0400 Received: from pb-smtp20.pobox.com (pb-smtp20.pobox.com [173.228.157.52]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 561B574DDB for ; Mon, 10 Oct 2022 10:27:15 -0700 (PDT) Received: from pb-smtp20.pobox.com (unknown [127.0.0.1]) by pb-smtp20.pobox.com (Postfix) with ESMTP id ABD181CBE3D; Mon, 10 Oct 2022 13:27:12 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=Xh4kwe1wQ6JCMuN0VXqW1vheZAqiNLA6wSAOQ6 eqoeg=; b=NGVgKL6uQBasAwOvqAQb3b/xBeNxugDfsOtcPaK8AVuF8dE/8MQMHu uuVuHVVu3ZoXwcDx5CyXpnspc8xtzMAcxdCBjjSG0Fn68AVVehSXZieRmbc1rPKj LM4AMjLVjo+Pb3OLI/pAaGQKkD9Uqmc/z803ZlGxh65WOHqglDQP0= Received: from pb-smtp20.sea.icgroup.com (unknown [127.0.0.1]) by pb-smtp20.pobox.com (Postfix) with ESMTP id 992361CBE3C; Mon, 10 Oct 2022 13:27:12 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.83.5.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp20.pobox.com (Postfix) with ESMTPSA id CB2E11CBE3B; Mon, 10 Oct 2022 13:27:09 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: "Derrick Stolee via GitGitGadget" Cc: git@vger.kernel.org, me@ttaylorr.com, newren@gmail.com, avarab@gmail.com, mjcheetham@outlook.com, steadmon@google.com, Glen Choo , Jonathan Tan , Teng Long , Derrick Stolee Subject: Re: [PATCH v4 08/11] bundle: add flags to verify_bundle(), skip walk References: <83f2cd893a4c47c947a93fe99d202d67f540e963.1665417859.git.gitgitgadget@gmail.com> Date: Mon, 10 Oct 2022 10:27:08 -0700 In-Reply-To: <83f2cd893a4c47c947a93fe99d202d67f540e963.1665417859.git.gitgitgadget@gmail.com> (Derrick Stolee via GitGitGadget's message of "Mon, 10 Oct 2022 16:04:16 +0000") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Pobox-Relay-ID: C53EDB3C-48C0-11ED-8F69-C2DA088D43B2-77302942!pb-smtp20.pobox.com Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org "Derrick Stolee via GitGitGadget" writes: > From: Derrick Stolee > > The verify_bundle() method checks if a bundle can be applied to a given > repository. This not only verifies that certain commits exist in the > repository, but Git also checks that these commits are reachable. > > This behavior dates back to the original git-bundle builtin written in > 2e0afafebd8 (Add git-bundle: move objects and references by archive, > 2007-02-22), but the message does not go into detail why the > reachability check is important. > > Since verify_bundle() is called from unbundle(), we need to add an > option to pipe the flags through that method. All makes sense. > When unbundling from a list of bundles, Git will create refs that point > to the tips of the latest bundle, which makes this reachability walk > succeed, in theory. However, the loose refs cache does not get > invalidated and hence the reachability walk fails. By disabling the > reachability walk in the bundle URI code, we can get around this > reachability check. The above makes it sound like the real culprit is that cache goes out of sync and the presented solution is a workaround; readers are left in suspense if the "real" solution (as opposed to a workaround) would come in a later step or in a future series. > diff --git a/bundle-uri.c b/bundle-uri.c > index 8a7c11c6393..ad5baabdd94 100644 > --- a/bundle-uri.c > +++ b/bundle-uri.c > @@ -301,7 +301,13 @@ static int unbundle_from_file(struct repository *r, const char *file) > if ((bundle_fd = read_bundle_header(file, &header)) < 0) > return 1; > > - if ((result = unbundle(r, &header, bundle_fd, NULL))) > + /* > + * Skip the reachability walk here, since we will be adding > + * a reachable ref pointing to the new tips, which will reach > + * the prerequisite commits. > + */ > + if ((result = unbundle(r, &header, bundle_fd, NULL, > + VERIFY_BUNDLE_SKIP_REACHABLE))) > return 1; This is not a new problem introduced in this new round, but if we are updating this, can we fix it to omit assignment inside if condition? * result is initialized to 0. * when unbundle returns non-zero, it is assigned to result and the function returns immediately, discarding whatever was assigned to the variable. * if unbundle returns zero, it is assigned to result and the control continues from here. We know result is set to 0, but then that is what it was initialized earlier.